As central processing units of electronic computers operate at increasingly higher speeds, it is required that terminal units of high speed printing apparatus also operates at higher speeds.
Heretofore high speed printers have been made by various means. This invention relates to a dot printer for printing characters or the like by means of a dot matrix. Typical printers using dot matrix for expressing characters of the like are, wire dot printer, thermal printer etc., and these are known. The spacing speed of these printers has a substantial effect on distance between any adjacent column of the dot matrix characters. This means when using the dot printer, any dot is printed on each column at a predetermined timing, and thus increased or decreased spacing speeds results in widened or narrowed column dot distances, causing the characters to be printed with uneven spacing from each other. Hence it is desirable that the printing elements perform spacing operations at a predetermined constant speed. It is difficult, however, to maintain the predetermined speed throughout the whole spacing operation because of the performance properties of the driving mechanism for the spacing operation, the mass of the printing head in which the printing elements are contained and so forth. Moreover in the case of high speed printing, the speed of the printing operation of the printing elements becomes less negligible, compared with that of the spacing. Accordingly it is required to adjust the print timing in relationship to the variation of the spacing speed.